1. Field of the Invention
The present invention relates to a semiconductor wafer including a compound semiconductor layer and a method of manufacturing a semiconductor device.
2. Description of the Related Art
Generally, semiconductor devices are manufactured by forming a plurality of semiconductor devices in a semiconductor wafer and dividing the semiconductor wafer into a plurality of chips for each semiconductor device. If there is a comparatively hard layer remaining in dicing lines at which the semiconductor wafer is to be cut, the blade cutting the semiconductor wafer can be badly damaged. For example, if a semiconductor wafer including a compound semiconductor layer, such as a gallium nitride (GaN) layer, formed on a silicon (Si) substrate is cut by a blade, the blade is more damaged than in the case where a Si wafer is cut. Moreover, vibration caused during dicing due to the damage of the blade will cause cracks or damages in semiconductor devices, resulting in a low yield. On the other hand, for the purpose of preventing the damages of the blade or preventing the low yield, it is possible to use a blade made of a special material or structure or employ a special dicing method. However, this will increase the manufacturing cost.
Accordingly, in one of the proposed methods, in order to prevent cracks from occurring in semiconductor wafers at dicing, grooves are formed on the both ends of each dicing line.
The aforementioned method could reduce the damages on semiconductor devices due to cracks or the like, but the blade will get damaged badly when cutting the hard compound semiconductor layer remaining in the dicing lines, in addition, the yield at dividing semiconductor wafers reduces.